life freestyle or get caught …

Single-/Multiple-Views: When using Descriptors which work on multiple views. Make sure to choose one (JCas cas = casIn.getView("yourView")) to work on. Otherwise you will miss AnnotatorIndexes and all, because UIMA doesn't choose a default view . Rather it creates a basic Cas and puts views as Cas's into that basic Cas. That's nothing new when you read the manual properly, I guess.

Sofa-Mapping: When mapping Sofas in agregate AEs you need to understand the mapping like this: You can create a Sofa (inout or output, just as in normal AEs) and associate ist with any input/outout Sofa from the aggregate's components. Which can be done (and is represented exactly in that manner) with the "Sofa Mappings"-dialog. NOTE: When working with single view AEs, it can happen that you need to edit the XML-Code a little.

Configuration: When creating AEs in your java code you will at some point have to configure it. You can do this by i.e. using setConfigParameterValue(String, Object) AFTER initializing ... when trying to configure them before initializing you need to set properties in the descriptor. When configuring after initialzing, don't forget to call regonfigure(), otherwise there's no guarantee, that your setting will take effect.